Influence of Preoperative Physical Function Scores on Outcomes After Single-level Cervical Disc Replacement.

Study design: Retrospective study.

Objective: We aim to determine the influence of preoperative Patient-Reported Outcome Measurement Information System Physical Function (PROMIS-PF) scores on perioperative and postoperative outcomes, the latter determined through patient-reported outcome measures (PROMs) and the degree of achievement rates of minimum clinically important difference (MCID) following single-level cervical disc replacement (CDR).

Background: Several studies have examined the relationship between preoperative PROMIS-PF as a prognostic factor for postoperative outcomes. Few studies have examined this relationship as it applies to CDR.

Methods: Patients undergoing single-level CDR with preoperative PROMIS-PF scores were identified retrospectively using a single-surgeon database. Patients undergoing surgery for infection/fracture/malignancy were excluded. Patients were divided by mean preoperative PROMIS-PF score: lower-functioning (PROMIS-PF <40) and higher-functioning (PROMIS-PF ≥40). Patient-Reported Outcomes Measurement Information System (PROMIS-PF), 12-item Short Form Physical Component Score (SF-12 PCS), Visual Acuity Scale (VAS) scores for neck and arm, and Neck Disability Index scores, collected at preoperative, 6-week, 12-week, 6-month, and 1-year time points.

Results: Fifty-seven patients were included with 33 considered higher functioning. Operative times were increased in the higher-functioning group (P = 0.003). The lower-functioning cohort saw improvement in all 6-week/12-week/6-month PROMs. The higher-functioning cohort saw improvement in all PROMs except SF-12 PCS. Between groups, the higher-functioning cohort reported greater postoperative PROMIS-PF at multiple time points, preoperative SF-12 PCS, 12-week/preoperative VAS-neck, and preoperative VAS-arm (P ≤ 0.036, all). The lower-functioning group had greater preoperative/6-week Neck Disability Index (P ≤ 0.027, all) and had greater MCID achievement at 6-month SF-12 PCS/12-week VAS arm (P ≤ 0.026, all).

Conclusion: Independent of preoperative function, both groups reported improvement in all outcomes except for SF-12 PCS in the higher-functioning cohort. Between groups, the higher-functioning cohort had significantly better outcomes; however, this significance was not seen past 12 weeks for any PROM. MCID achievement rates were significantly greater in the lower-functioning group in the SF-12 PCS and VAS arm. Patients with lower preoperative PROMIS-PF scores may experience greater rates of clinically noticeable improvements in function/arm pain postoperatively.